Environmental campaigners called on Tony Blair yesterday to publish a briefing he used to justify hints that he would approve a new generation of nuclear power stations.

Friends of the Earth filed a freedom of information request on the "first cut" of the government's energy review - due to report before the summer.

Mr Blair told business leaders yesterday the "stark" facts he had been shown meant the nuclear question was "back on the agenda with a vengeance". He told MPs at question time that ruling out more use of the technology in the future would be "a collective dereliction of duty".

Tony Juniper, director of Friends of the Earth, said the energy review appeared to be a "sham" to mask Mr Blair's determination to press ahead with nuclear energy.

"Tony Blair has completely undermined the government's energy review by endorsing a new generation of nuclear power stations," he said.

"He must publish details of the briefing he received from the DTI, which he has now made so public, so that we can have a transparent and open debate on this issue," Mr Juniper said. "The UK should be leading the way in developing a sustainable energy strategy for the 21st century, rather than championing dirty, dangerous and expensive nuclear power."

Nuclear power is only just coming back on to the European and American energy agenda after decades in the wilderness after the Chernobyl and Three Mile Island accidents. Mr Blair's declaration makes him the latest in a growing band of leaders taking their countries down the nuclear path.

According to the World Nuclear Association 16 countries, not including Iran, now have proposals to build 107 new civil reactors. The majority are in Asia. Of 27 nuclear stations now under construction worldwide, 16 are in China, India, Japan and South Korea. India is considering building more than 20 plants in the next 15 years and China at least 40. South Africa has said it wants 24 reactors. No new nuclear station has been ordered in the US for 25 years, and only one European reactor is under construction, in Finland. Sweden and Belgium are more or less committed to phasing out existing plants and Austria, Denmark and Ireland have stated policies against nuclear energy.

Building costs are the biggest stumbling block to new plants and Mr Blair will be looking carefully at the kind of sweeteners that President George Bush is providing in the US.

Up to 12 stations are being considered in the US and the energy bill, signed in 2005, includes "risk insurance" money for the first six builders of plants.

Up to $500m (£400m) has been promised to builders of the first two and $250m for each of the next four

The industry is also using climate change as the intellectual launchpad for its revival. When up and running, the power generated is practically emission-free and therefore highly attractive to countries finding it hard to meet their global warming obligations.

What is less recognised is that if the emissions from building stations, decomissioning them and extracting the uranium to fuel them are factored in, nuclear power is not always much cleaner than some fossil fuel power.